Republican presidential candidate Donald Trump brought up the former Soviet Union’s excursions into the Middle East in predicting Russia will get “bogged down” with the current conflict in Syria, calling to mind a point the White House also made Wednesday.

“The biggest problem I have is that you look at what’s gone on with Libya, with Gaddafi, and Iraq, with Saddam Hussein, and with all these people that we’ve been fighting against, and the problem is far greater,” Mr. Trump said Thursday on “Fox and Friends.” “I mean, Iraq is a … total disaster. But Iraq led to the Middle East. Then you look at Libya — total disaster.”

“You know, we’re supposed to be fighting with rebels — we have no idea some of the people,” he said. “I spoke to one of the generals. They [don’t] even know who they are fighting for. Is it worse than [President Bashar] Assad? What’s going on?”

“And I do say this: Russia destroyed itself, you know, when it was the Soviet Union. They spent so much money in Afghanistan, they got bogged down,” he said. “You watch — I bet they get bogged down again. They’re going to go in here. They’re going to get bogged down again.”

White House press secretary Joshua Earnest said Wednesday that President Obama and Russian President Vladimir Putin had agreed that there needs to be a political solution to problems going on in Syria.

“That means Russia will not succeed in imposing a military solution on Syria any more than the United States was successful in imposing a military solution on Iraq a decade ago, and certainly no more than Russia was able to impose a military solution on Afghanistan three decades ago,” Mr. Earnest said.

“I fully understand both sides of the picture, but I think we have to be very cool. Let’s just see what happens,” Mr. Trump said, saying we don’t want to move too fast. “They’re probably going to be, based on everything else we’ve seen with Iraq and with Libya, they’re probably going to be worse than what you have in right now. And what you have in right now is very bad.”

“You don’t want to jump in for people that we don’t even know who they are,” he said. “We’re fighting for people that we have no idea who these rebels are. I’ve heard the rebels are worse than anybody else. I mean, they could be ISIS. We have no idea who they are.”

“ISIS is absolutely the enemy and we have to do something very strong against ISIS. … Frankly, we should be bombing the hell out of them,” Mr. Trump said. “You have to go beyond the lines of Syria here. We’re talking about Syria, but ISIS is in Iraq, very big league.”

“Remember this: We’re fighting for people that we have no idea who they were,” he said. “Some of ‘em we didn’t even know until recently. And by the way, they could be ISIS — we could be fighting for ISIS. So I think we have to be very cool, I’ll be honest. And that’s not usually the way I am. … I want to be very proactive, but I think we have to watch it, see.”

Mr. Trump also said he thinks Russia has a big stake in getting rid of the Islamic State.

“If I knew who these people were, if we thought they were George Washington, if we thought they were great, I’m all for [you], but we have to find out. We have no idea who we’re fighting for,” he said. “And it could be worse than Assad. As bad as he is — he’s bad — but it could be worse than Assad.”